What is rate law? Give a relation between rate of reaction and concentration of reactants.

(N/A) The rate of a chemical reaction depends upon experimental conditions such as the concentration of reactants (or pressure in the case of gases),temperature,and the presence of a catalyst.
The representation of the rate of a reaction in terms of the concentration of the reactants is known as the rate law. It is also referred to as the rate equation or rate expression.
For a general reaction $aA + bB \rightarrow \text{Products}$,the rate law is expressed as:
Rate $= k[A]^x[B]^y$
where $k$ is the rate constant,and $x$ and $y$ are the orders of reaction with respect to reactants $A$ and $B$,respectively.
The rate of a reaction generally decreases as the concentration of reactants decreases over time. Conversely,the rate increases when reactant concentrations increase.
Therefore,the relationship is:
$\text{Rate of reaction} \propto [\text{Reactants}]$
Thus,the rate of a reaction is directly proportional to the concentration of the reactants raised to some power.